Stupid Questions

[LifeofPhil]

so a few stupid questions:

on the user manual of my bike it says: "if the cock lever is set to the Off position the fuel supply will stop. Always set the cock lever to the position after use."

why should I do this? how doe it help?

(more stupid questions to follow)

[bonio]

I guess this is talking about the fuel cut off? (which I think looks like this)

Can't think why you'd turn to off, except of course in an emergency.

[LifeofPhil]

yeah that's it, switches between on off and reserve tank.

[iangaryprice]

It recommends switching to off to ensure no fuel will flow (leak out).

The float and needle valve on the carb should stop the fuel, but they can stick, if this happens fuel can continue too flow and will leak out causing the risk of fire etc.

Many newer/larger bikes have a "vacuum fuel tap (cock)"

The flow of fuel on this is controlled by vacuum from th engine.

When the engne is not running there is no vacuum so no fuel flows. Hence you can leave this type of tap switched on.

[Tango]

Exactly.....to prevent your tank emptying its contents if the float sticks in the carb.......worst case scenario is that it fills the airbox with fuel, which can then allow the fuel into the sump, via the crankcase breather.....

[bonio]

Ooh. Learn something every day.

[marcom]

Regular or premium fuel?

[fastbob]

Exactly.....to prevent your tank emptying its contents if the float sticks in the carb.......worst case scenario is that it fills the airbox with fuel, which can then allow the fuel into the sump, via the crankcase breather.....

 

Yep, a very common occurrence well known to ER5 owners.only problem is that most fuel taps don't have an off position more's the pity. I had a cylinder fill with fuel overnight on my way to Scotland this year causing a hydraulic lock . I had to remove a plug and hit the starter . The resulting eruption covered me from head to foot in petrol , fortunately I quit smoking years ago. At least it proves I have good compression.

[oldgrump]

Hi, Had 4 bikes that have hydraulic lock out's, 25 years ago a neighbours VF500, a Z1100R, and a Suzuki GSXR750!!! with a vacuum tap that had stopped working and not shutting off fuel, and the most frightening Suzuki VS700 trike, this year on the bench front cylinder cut out, but the carb is above cylinder and spark plug!!!! before I realised what was happening the fuel was pumped all over the front plug!! yep it burst into flames!! Bloody good job I keep fire extinguishers handy!!! And as Fastbob has said stand back when you take plugs out, you may get wet

[fastbob]

Regular or premium fuel?

 

Pepsi or Coke ?

[LifeofPhil]

Thanks guys! I need to get a manual and start taking apart and rebuilding the bike to learn and understand it all.

[fastbob]

Thanks guys! I need to get a manual and start taking apart and rebuilding the bike to learn and understand it all.

 

Haynes Motorcycle Basics is a good place to start.

[LifeofPhil]

Haynes Motorcycle Basics is a good place to start.

 

I just orderd Haynes Chinese 125cc motorcycles. Hopefully will give me more of an insight.

[TimR]

They are known as a Petcock

I take no responsibility for any google results that may occur if that term is searched for

[TimR]

Some bikes had no overflow prevention in the carbs and if it did overflow the fuel would enter the engine via the inlet valves and cause hydrolock resulting in bent valves and conrods

[TimR]

It recommends switching to off to ensure no fuel will flow (leak out).

The float and needle valve on the carb should stop the fuel, but they can stick, if this happens fuel can continue too flow and will leak out causing the risk of fire etc.

Many newer/larger bikes have a "vacuum fuel tap (cock)"

The flow of fuel on this is controlled by vacuum from th engine.

When the engne is not running there is no vacuum so no fuel flows. Hence you can leave this type of tap switched on.

Gtr1000 have this and is the biggest cause of knackered engines due to the diaphragm weakening and then allows the tank to drain .

[fastbob]

Haynes Motorcycle Basics is a good place to start.

 

I just orderd Haynes Chinese 125cc motorcycles. Hopefully will give me more of an insight.

 

It will give you an insight into Chinese 125cc motorcycles most of which have engines based on the Honda CG125 . Motorcycle Basics, on the other hand, will give you a broader understanding of the mechanical principals of all types of motorcycle and will stand you in good stead for the rest of your life. I recommend you buy both if you intend to stick with bikes.

[LifeofPhil]

I recommend you buy both if you intend to stick with bikes.

 

f*ck yeah! this little 125 is just the beginning. In the next two years I hope to learn enough to rebuild my Granddad's BSA Lightning and get it on the road. I will prob not be able to do it all by myself but I would like to think I could develop the skills to get it started.

[fastbob]

I recommend you buy both if you intend to stick with bikes.

 

f*ck yeah! this little 125 is just the beginning. In the next two years I hope to learn enough to rebuild my Granddad's BSA Lightning and get it on the road. I will prob not be able to do it all by myself but I would like to think I could develop the skills to get it started.

That's great to hear, oddly enough a typical Chinese bike has something in common with a BSA in that the engine is push rod operated and not overhead cam .

[LifeofPhil]

ok more stupid questions:

I'm trying to trouble shoot power issues.

The bike has died on me a few times and not been able to restart. I charged the battery over night about 10 hours, but the bike died again the next day. I have put a new battery in today and it starts no problem, but how can I tell if the Alternator is working? (also Alternator is what charges the battery as i ride right?)

Bike details

125cc Lexmoto Aspire

battery is a Halfords Hb9-b

the bike has an added alarm and remote ignition (I will be removing the remote ignition once i know more about the electrics and workings of the bike)

[fastbob]

I were you though I'd wait for the postman to deliver your Chinese bikes manual first. In the meantime I'd pop into Wilkinsons and buy a multi meter for about £13. This procedure is bound to be covered by the book. You are quite right, the alternator does charge the battery but there is a pesky thing called a regulator rectifier as well that can go wrong.

[RantMachine]

It will give you an insight into Chinese 125cc motorcycles most of which have engines based on the Honda CG125 . Motorcycle Basics, on the other hand, will give you a broader understanding of the mechanical principals of all types of motorcycle and will stand you in good stead for the rest of your life. I recommend you buy both if you intend to stick with bikes.

Sound recommendation! Although I think that the DR/GS/GZ/GN125 engine is getting to be more common than the CG these days, it seems to be used in the majority of the offerings from Sinnis, Lexmoto, and Herald.

[fastbob]

It will give you an insight into Chinese 125cc motorcycles most of which have engines based on the Honda CG125 . Motorcycle Basics, on the other hand, will give you a broader understanding of the mechanical principals of all types of motorcycle and will stand you in good stead for the rest of your life. I recommend you buy both if you intend to stick with bikes.

Sound recommendation! Although I think that the DR/GS/GZ/GN125 engine is getting to be more common than the CG these days, it seems to be used in the majority of the offerings from Sinnis, Lexmoto, and Herald.

I've noticed that as well. Whenever I see a Chinese bike I always look at the left side of the barrel for the little round insert that is the cam follower shaft indicating push rod CG based origins . I'm seeing a lot more bikes without this that must be overhead cam operated. The ones that do slightly annoy me are those with twin exhausts and only one cylinder such as the inappropriately named Keeway Superlight .

[RantMachine]

Ah yeah, for me it's always that really distinctive DR125 oil filter cover that I look for first

I agree on the twin exhaust ones, surely it's just one more thing to rot? If they want to go for that look, I wish they'd make a copy of the CM125 engine instead of just jamming a second pipe onto a CG

[fastbob]

I reckon the Lexmoto Aspire is a YBR copy, or is it the other way round ? Probably not push rod then. As a whimsical aside, an impossible bike I'd love to own would be an original '76 CG but magically scaled up in every dimension to a 500cc thumper.